Light-weight bathtub structure



March l2, 1957 c. A. STRAND 2,784,417

LIGHT-WEIGHT BTHTUB STRUCTURE Filed ocr. 14, 1954 iff% United States Patent O 2,784,417 LIGHT-WEIGHT BATHTUB STRUCTURE Carl A. Strand, Birmingham, Mich.

Application October 14, 1954, Serial No. 462,260

Claims. (Cl. 4173) This invention relates to an improved light-weight bathtub construction, and more particularly, to an improved structure for supporting the light-weight bathtub or the like receptacle.

As is well known, the ordinary bathtub is a very heavy cast iron receptacle, which is expensive to produce and also to install. In addition, such cast iron bathtubs are extremely difficult to handle during shipment and installation because of their very great weight. This excessive weight also prevents or substantially limits the use of such bathtubs in living quarters wherein weight of fixtures is a distinct disadvantage, for example, in lightweight cabins, temporary houses, certain forms of prefabricated dwellings, and particularly in automobile trailer houses.

The substitution of other materials for the enamelcoated cast iron bathtub has, however, provided a problem which heretofore has gone unsolved, notwithstanding the very great need for bathtubs as units of substantially lighter weight. The enamel coating, which is employed for decorative purposes as well as for the purpose of simplifying the cleaning of the bathtub, is characterized by extreme brittleness typical of ceramic materials; and such enamel coating must be supported by an extremely strong and inflexible structure or shell in order to prevent fracture thereof during ordinary wear and tear, and particularly in response to sharp impact. The use of cast iron in the formation of such a shell has, therefor, been considered a necessity heretofore.

As is disclosed and claimed in United States application Serial No. 319,992, now Patent No. 2,695,256, entitled Light-Weight Bathtub and Production Thereof, filed November 12, 1952, in the names of Valentine De Olloqui, Carl A. Strand and Carroll H. Van Hartesveldt, and owned by the owner of the instant invention, a suitable light-weight bathtub has been found which has a suitably flexible or resilient enamel-like coating and integrally formed therewith a glass fiber-polyester laminated body of suitable strength and resiliency. Since this light-weight bathtub has the general shape of all bathtubs which is somewhat irregular in that the bottom tends to slope toward a drain and the extent to which the bottom is dished or bowed varies at different points longitudinally of the bathtub structure, the problem of providing a suitable practical and economical supporting device or means for this light-weight bathtub is somewhat complicated. The problem is further complicated by the fact that the overall resiliency or flexibility of the instant bathtub is such that it is not advisable to employ supports for the bottom of the bathtub which tend to cause sharp concentration of forces at one place or another in the bottom of the tub. As will be appreciated, such means of adequately supporting the bathtub as those which might be provided by forming plaster or concrete beds in which to seat the bathtub must involve an extensive amount Patented Mar. 12, 1957 ICC of additional work that is more or less inconsistent with the essentially economical features of the instant and light-weight bathtub. Most ideally, a simple but sturdy unit or device which may be prefabricated by the bathtub manufacturer and secured to the bathtub is required for the instant light-weight bathtub; and the instant invention resides in a unique and superior supporting arrangement of this type.

It is, therefore, an important object of the instant invention to provide an improved light-weight bathtub supporting assembly.

I t is a further object of the instant invention to provide an improved light-weight bathtub assembly, comprising a suitably formed glass liber-polyester laminated bathtub shell having the generally dish-shaped bottom thereof sloped downwardly longitudinally toward a drain end, and an attached support device providing beam strength for said bottom consisting essentially of a rigid layer of hardened binder material having l0 to 75% porosity and having its top surface contoured to conform to the shell bottom and secured thereto.

It is another object of the instant invention to provide an improved device for supporting from beneath a receptacle made of resilient high shear-resistant material and having a generally dish-shaped bottom sloping downwardly in a given longitudinal direction, that comprises longitudinally and laterally extending end and side frame members for the bottom of the receptacle defining therewith a mold form, the mold being filled with a hardenable binder material having 10 to 75 volume percent porosity to define a monolithic hardened bottom supporting layer of the material secured to the bottom of the receptacle.

Other and further objects, features and advantages of the instant invention will become apparent to those skilled in the art from the following detailed description of pre-k ferred embodiments thereof, and the attached drawing forming a part of the instant specification.

On the drawings:

Figure 1 is a side elevational view of the instant lightweight bathtub assembly embodying my invention;

Figure 2 is a sectional elevational view taken substantially along the line II-II of Figure l;

Figure 3 is an enlarged detail View showing fragmentarily the front panel and front top wall cooperation;

Figure 4 is a sectional elevational view taken along the line lV-IV of Figure 1 showing only the instant supporting device;

Figure 5 is a sectional elevational View taken substantially along the line V-V of Figure 1 showing only the supporting layer; and

Figure 6 is a sectional elevational view of the supporting layer which is positioned beneath the bathtub shell of Figure l, taken substantially along the line VI-VI of Figure l.

As shown on the drawing:

walls. The back side wall 13 extends upwardly and flares outwardly at 13a to engage and be supported by the bathroom wall W. As will be seen, the extreme top of the back wall 13 has an upwardly extending rib 13b which interlocks with suitably positione-d tile T mounted on the bathroom wall W in the usual manner. The tilel T and back wall W are shown essentially diagrammatically only in Figure 2 to avoid undue confusion in the drawings.

The end walls 14 and 15 like the back wall 13 extend upwardly and outwardly to define ridges 14b and 15b, respectively, which engage the walls W', W" and coact therewith in substantially the same manner that the back wall 13 engages and is supported by the bathroom wall W.

The remaining wall, the front wall 12, extends upwardly and near the top thereof (which is substantially uniplanar with the other wall tops 13a, 14a and 15a) at 12a is turned outwardly and down, so as to define in cross section at the top 12a a curved arch, as is best shown in Figure 3. The arch 12a terminates at its outer extremity 12b with a substantially downwardly directed rib portion. This end portion 12b seats firmly in the front groove 16a of an S-shaped elongated metal strip 16 which extends the full longitudinal direction of the shell 11 and arcuate front wall top 12a. The rear groove 16b of the S-shaped strip 16 securely seats the rounded top edge of a supporting panel 17 which extends vertically upwardly from the floor F. The plane of the floor F is substantially parallel to the plane P of the wall tops 12a, 13a, 14a and 15a. The panel 17 is rigidly secured to the floor F, for example, by means of a screw and bracket assembly 17a, and the panel 17 extends the full longitudinal dimension of the shell 11 and upwardly to substantially the height of the arcuate top 12a of the front wall 12. The panel 17 is made of suitably strong structural wood, plywood, heavy-weight laminate or the like material, which is capable of withstanding very substantial downward pressure and which is sufficiently rigidly secured to the oor F to resist substantial laterally directed forces, so as to afford a certain amount of protection for the front wall 12. The front wall 12 is made of a suitably strong glass fiber-polyester laminate material that is capable of withstanding very substan tial downwardly directed forces, and the front wall 12 and panel 17 (by virtue of its supporting engagement with the outer lip 12b of the front wall 12) cooperate to provide very substantial force-rcsisting support for the top arcuate portion 12a.

In this manner, the top arcuate portion 12a is capable of readily withstanding the ordinary wear and tear during the use of the instant bathtub assembly 10, and is particularly capable of withstanding the weight of human beings leaning on or pulling against the arcuate portion 12a, while getting in and out of the bathtub 10. lt

will be appreciated that the panel 17 may be easily int stalled at the same time the bathtub 10 is installed and the panel 17 may be prefabricated of the desired weight and strength to carry out its particular function just described. It will also be appreciated that in the use and installation of the ordinary cast iron bathtub a structure generally similar to the instant shell structure 11 is employed with a depending wall member, also made of cast iron, which takes the place of the panel 17. ln such an arrangement the depending wall member furnishes the sole support of substantially the entire weight of the cast iron tub, and the top edges of the other walls of the top shell are suitably affixed to the bathroom walls.

The instant top shell 11 is, however, not supported entirely by the panel 17. In fact, because of its light weight and other advantageous features connected therewith, the overall shell 11 is too resilient in character to be supported by the panel 17 alone. It is also necessary to employ a suitable supporting device 18 which is centrally positioned beneath the top shell 11.

As will be seen, the device 18 is an attached support device providing beam strength for the bottom 11a of the shell 11 and is constructed of a rigid layer 19 (which will be described in detail hereinafter) having its top surface 19a contoured to conform to the shell bottom 11a and secured thereto, longitudinally extending side wall members 20 and 21 and laterally extending end wall members 22 and 23 protectively surrounding the layer 19 and secured to the shell bottom 11a, and a bottom wall member 24 cooperatively secured to the outwardly or downwardly extending surfaces of the end and side wall members 20, 21, 22 and 23 and conforming to and secured to the bottom surface 19b of the layer 19. As will be seen, the wall members 20, 21, 22 and 23 are elongated longitudinally and laterally extending support beams protectively surrounding the layer 19 and secured to the shell bottom 11a, most preferably by a suitable adhesive.

It will also be seen that the device 18 is suitably mounted on the floor level F and extends upwardly to support the central portion of the shell bottom 11a, which is itself a generally dish-shaped bottom that is sloped downwardly in the (longitudinal) direction of a drain 25, and which becomes decreasingly bowed or dished in shape in the longitudinal direction toward the drain 25 (or the drain end 14 of the shell 11).

The details of composition and construction of the shell 11 are disclosed at length in preivously mentioned copending application entitled Light-Weight Bathtub and Production Thereof, and these details need not be further elaborated upon herein. In general, the instant top shell 11 is a slightly resilient or exible laminate possessing extremely high shear resistance, having an approximate wall thickness of about 0.08 inch and being composed essentially of polymerized polyester laminating resin having embedded therein about one-half the weight thereof of glass fibers, with a highly pigmented coating on the inside which is rendered equally resilient by the incorporation therein of a substantial proportion of a flexible polyester.

A particularly important aspect of the instant invention resides in the structural arrangement of the device 18, and in the fabrication thereof so as to obtain the desired structural arrangement. The device 18 is a simple and sturdy unitary device that may be prefabricated by the manufacturer of the light-weight bathtub and permanently secured to the bottom 11 of the bathtub at its point of manufacture thereby avoiding the necessity for the customer or the person installing the bathtub to handle and properly place a separate base or rack element.

Referring now to details of certain of the elements of the device 18, it will be seen that the device 18 constitutes an attached support device for the more or less irregularly contoured bathtub shell bottom 11, which comprises a plurality of spaced laterally extending support beams, or end walls 22 and 23, each adapted to rest upon a level surface, such as the bottom wall member 24 (or the oor surface F if the bottom 24 is not employed, or is made to t within the wall members 20, 21, 22 and 23), and extending upwardly to supportingly contact the shell bottom 11 thereabove, each of the end walls or beams 22 and 23 presenting tops 22a and 23a suitably curved to conform with the portion of the shell bottom 11 positioned thereabove. As will be seen from Figures 4, 5 and 6, the shell bottom 11 becomes decreasingly bowed or less sharply dished in the longitudinal direction toward the drain end 14, so that the curved top 23a of the rearmost beam 23 is quite clearly bowed and the top 22a of the forwardmost beam 22 is very slightly bowed. It will also be noted that the rearmost beam 23 extends to a noticeably greater height than the forwardmost beam 22, so that the downward slope of the shell bottom 11 in the direction of the drain 25 is also provided for by the instant beam arrangement. It will also be appreciated that a suitably compartmented rack might also be constructed using more than two of the laterally extending end walls.

As is shown in Figures 4, 5 and 6, the -side walls 20 and 21 are also shaped with top faces which conform substantially to the slope of the bottom 11a, as well as the curvature thereof at the portion contacted by the top 20a or 21a of each of the side walls 20 and 21. As shown in the instant embodiment, the bottom bases of each of the walls 20, 21, 22 and 23 are substantially uniplanar, and are suitably affixed to the bottom wall 24 by screws or nails (not shown) or by a suitable adhesive. In this embodiment, the bottom member 24 is substantially fiat and is adapted to rest flush upon the floor. The adjustments in the instant base device 18 for the variations in contour and slope of the shell bottom 11a are thus made in the wall members 20, 21, 22 and 23 and in the layer 19 itself.

The instant layer 19 is a light-weight monolithic layer of hardened binder material having l0 to 75 volume percent porosity; and this layer 19 affords a number of advantages in its use as well as in its formation. The layer 19 is made from a moldable or plastic mass which is aerated or foamed in order to obtain the desired porosity and allowed to set in the rigid form here shown, or it is admixed with a void-containing aggregate or filler, which, through its own porosity, will impart to the layer in which this filler is embedded the required porosity here indicated.

The purpose of the porosity i-s to lighten the weight of the binder material defining the layer 19. The amount of porosity which is provided for the binder material will, of course, vary to some extent depending upon the particular type of material used; but in general, the porosity will vary from a minimum of about (below which the decrease in weight is not appreciable in the layer 19) to a maximum of about 75% which is about the most porosity which ordinary binder materials can have without being too weak to serve the purpose here involved. The instant layer 19 has reduced weight because of the porosity therein and it also has sufficient compressive strength to serve the purpose here involved, which is sufficient compressive strength to support the weight of a person standing in the bathtub. For practical purposes, the compressive strength should be sufficiently great that each square inch of surface area of the layer 19 should have the compressive strength sufiicient at least to support 200 to 300 pounds (or the maximum weight expected of a person using the bathtub).

A number of layer `structures have been found suitable and these include those using synthetic resin binders, or fusion-integrated binders generally, or hydration-setting type cements.

The binder is a hydration-settable type cementitious binder such as the cement, lime and gypsum binders commonly used in concrete, mortar, plaster and like masonry. In general, each of such binders comprises initially a dehydrated or calcined substance such as Portland cement, lime and gypsum, which is capable of chemically combining with water admixed therewith so as to harden or set to form an article of the substantial strength required for construction.

It is well known that such calcined material, in the presence of suitable particulate siliceous aggregate, may be slaked or admixed with water in an amount suf-lcient to impart somewhat viscous fluidity or plasticity thereto, but also in an amount such that a substantial proportion of the water present may be chemically combined therewith during the setting or hardening process. The most recent studies of the actual mechanics of the setting operation indicate that the initial setting operation involves the chemical phenomenon of hydration, although subsequent phenomena efecting the final or complete setting of the material may involve reactions such as the combination of hydrated lime with carbon dioxide from the air, the formation of silicate of lime by reaction of hydrated lime with silica in the aggregate, and the crystallization action of water on silicate of lime. In any event, however, the initial hardening or setting action here involved is principally a hydration reaction, and for the purposes of the instant invention -such masonry binders are herein referred to as hydration-settable type cementitious binders or materials. ln dry and in slaked condition prior to setting the materials are hydration-settable, and after setting they are hydration-set.

In concrete, for example, the binder is usually a mixture of calcium aluminates and silicates, prepared by burning a mixture of calcareous and argilla'ceous materials to clinkering temperature and grinding the resulting clinker. Such a binder is generally referred to as Portland cement. In mortar, the binder usually is Portland cement or calcined lime, such compositions being referred to as cement mortar and lime mortar, respectively. In plaster, the binder usually comprises calcined lime or calcined gypsum (CaSO4), plaster of Paris comprising a partially dehydrated gypsum, CaSO4.1/2H2O. The so-called quick hardening cements contain a substantial quantity of alumina (A1203). Various other ingredients, including magnesium oxide (MgO) may also be used to participate in dehydration-setting reaction herein involved.

Also, the fusion integration type binder may be used and this binder is one that is suitable for use in fusion integration whereby the binder is capable of undergoing an initial fusion during the shaping and integration of the layer. Such a binder may be permanently thermoplastic in that it may be repeatedly used or melted, or such a binder may be thermosetting, such as certain of the synthetic resins which are capable of undergoing an initial heat-effected fusion, but which subsequently are set by the reaction of the heat so as to form a substantially infusible material. A preferred fusion integration type binder is one of the so-called cold-setting laminating or adhesive synthetic resin-s. These resins are a known class which are capable of setting to form rigid monolithic resinous bodies at conditions of temperature and pressure which are no more drastic than those employed in the formation of the instant polyester laminated bathtubs.

The resin or adhesive used may be any one of a number of suitable laminating or adhesive natural or synthetic plastic materials, which include phenol-aldehydes (phenolformaldehyde), urea-aldehydes urea-formaldehyde) polyesters (unsaturated dihydric alcohol-dicarboxylic acid condensation products such as ethylene glycol maleate alkyd), modified rosins or rosin modified alkyds, etc. Most preferably, however, urea-formaldehyde resin is employed.

In general, each of the various types of cement or adhesive binders herein described may be used in the practice of the instant invention. The synthetic resin binders afford the additional advantage that they have specific gravities within the range of about l to 1.5; but the hydration-settable type materials are capable of being formed in highly porous structures having relatively high compressive strengths. As previously mentioned, the porosity should be about l0 to about 75 volume percent of the layer, and preferably the porosity is about 40-60%. As mentioned, the porosity may be imparted to the layer by suitable foaming processes, all of which are well known in the art. By the use of these procedures, aerated or foamed concrete, plaster, etc. may be used as well as aerated or foamed thermosetting resins (i. e., urea-formaldehyde) and thermoplastic resins (i. e., styrene). Also, and more preferably, the porosity is provided by the use of void-containing aggregates such as expanded vermiculite, perlite, spherulized clay particles. etc.

Because of the porous nature of the instant materials, such materials are cured or set in the absence of any appreciable pressure and, as previously mentioned, at curing or setting temperatures between about room temperature and about 200 F. (and preferably not more than about 100 F.). Examples of typical formulations are as follows:

In general, the bathtubs per se weigh about 10 pounds; and the base weighs not more than about 2O pounds and most preferably about 8-12 pounds.

The layer 19 may be formed in a suitable separate mold with a master form having the shape of the bottom 11a (and covered with a layer of protective material which may be retained on the layer top 19a and used to adhesively secure the Same to the bottom 11a) or the layer 19 may be formed and adhered to the bottom 11a in situ as will be described.

The advantage of the instant invention is that the layer 19 may be formed separately or it may be formed directly on the bottom of the tub shell 11. This latter procedure offers a very distinct advantage because the molding procedures for receptacles of the size of the instant shell 11 are such that absolutely uniform contour in the bottom of the shell 11 is not obtained consistently in many cases. In view of this, it is difficult to make separate bottom mounting means which can be adequately aiiixed to the bottom of the shell 11. Accordingly, a particular advantage of the instant invention resides in the process of providing the longitudinally and laterally extending end and side frame members 20, 2l, 22 and 23, in the positions here indicated secured to the bottom of the receptacle 11, so as to define a mold form. In this operation, the tub is turned upside down and the wall members 20, 21, 22 and 23 are secured thereto by adhesives or the like materials and the hardenable binder material, which has been foamed or has had incorporated therein a void-containing ller, is poured into the mold form thus provided and the top is leveled off (in the shape here indicated) and the material is allowed to set (and thereby adhere to the bottom 11a). Then the bottom member 24 may be applied. wall members 20. 2l, 22 and 23 are mounted so that their outwardly extending faces will lie in a plane that is substantially parallel to the plane P defined by the wall tops 12a, 13a, 14a and 15a, so that the layer 19 will in effect define a plane that is substantially the oor plane F when the tub is mounted upright. The bottom wall 24 thus mounted on the bottom face 19b of the layer 19 may be a substantially flat piece of wood or similar material which is so positioned primarily for the purpose of protecting the porous layer 19 against impact, etc.

lt will be understood that modifications and variations may be effected without departing from the scope of the novel concepts of the present invention.

I claim as my invention:

l. A light-weight bathtub assembly, comprising a glass fiber-polyester laminated bathtub shell having a generally dish-shaped bottom therefor sloped downwardly longitudinally toward a drain end, and an attached support device providing beam strength for the bottom constructed of a rigid monolithic layer of hardened binder material having l() to 75 volume percent porosity and having its top surface contoured to conform to the shell bottom and secured thereto.

2. A light-weight bathtub assembly, comprising a In this operation, the side t glass liber-polyester laminated bathtub shell having a generally dish-shaped bottom therefor sloped downwardly longitudinally toward a drain end, and an attached support device providing beam strength for the bottom constructed of a rigid monolithic layer of hardened hydration-settable type cementitious material having l0 to 75 volume percent porosity and having its top surface contoured to conform to the shell bottom and secured thereto.

3. A light-weight bathtub assembly, comprising a glass fiber-polyester laminated bathtub shell having a generally dish-shaped bottom therefor sloped downwardly longitudinally toward a drain end, and an attached support device providing beam strength for the bottom constructed of a rigid monolithic layer of hardened binder material of the class consisting of Portland cement, lime, gypsum and mixtures thereof having l0 to 75 volume percent porosity and having its top surface contoured to conform to the shell bottom and secured thereto.

4. A light-weight bathtub assembly, comprising a glass fiber-polyester laminated bathtub shell having a generally dish-shaped bottom therefor sloped downwardly longitudinally toward a drain end, and an attached support device providing beam strength for the bottom constructed of a rigid monolithic layer of hardened binder material having l0 to 75 volume percent porosity and having its top surface contoured to conform to the shell bottom and secured thereto, said porosity being provided by the presence of a porous light-weight filler embedded in the monolithic layer.

5. A light-weight bathtub assembly, comprising a glass ber-polyester laminated bathtub shell having a generally dish-shaped bottom therefor sloped downwardly longitudinally toward a drain end, and an attached support device providing beam strength for the bottom constructed of a rigid monolithic layer of hardened hydration-settable type cementitious material having 10 to 75 volume percent porosity and having its top surface contoured to conform to the shell bottom and secured thereto, said porosity being provided by the presence of a porous light-weight filler embedded in the monolithic layer.

6. A light-weight bathtub assembly, comprising a glass fiber-polyester laminated bathtub shell having a generally dish-shaped bottom therefor sloped downwardly longitudinally toward a drain end, and an attached support device providing beam strength for the bottom constructed of a rigid monolithic layer of hardened synthetic resin binder material having l() to 75 volume percent porosity and having its top surface contoured to conform to the shell bottom and secured thereto.

7. A light-weight bathtub assembly, `comprising a glass fiber-polyester laminated bathtub shell having a generally dish-shaped bottom therefore sloped downwardly longitudinally toward a drain end, and an attached support device providing lbeam strength for the bottom constructed of a rigid monolithic layer of hardened synthetic resin binder material having l() to 75 volume percent porosity and having its top surface contoured to conform to the shell bottom and secured thereto, said porosity being provided by the presence of a porous light-weight filler embedded in the monolithic layer.

8. A light-weight bathtub assembly comprising a glass fiber-polyester laminated bathtub shell having a generally dish-shaped bottom therefor sloped downwardly longitudinally toward a drain end, and an attached `support device providing `beam strength for the bottom constructed of a rigid monolithic layer of hardened urea-formaldehyde resin binder material having l0 to 75 volume percent porosity and having its top surface contoured to conform to the shell bottom and secured thereto, said porosity being provided by the presence of perlite lillcr embedded in the monolithic layer.

9. A light-weight bathtub assembly, :comprising a glass fiber-polyester laminated bathtub shell having a generally dish-shaped bottom therefor sloped downwardly longitudinally toward u drain end, an attached support device providing beam strength for the bottom constructed of a rigid monolithic layer of hardened binder material having 10 to 75 volume percent porosity and having its top surface contoured to conform to the shell bottom and secured thereto, elongated longitudinally and laterally extending support beams protectively surrounding said layer and secured to the `shell bottom, and a bottom wall member cooperatively secured to the bottom of said support beams and conforming to and secured to the bottom surface of said layer.

10. A light-weight bathtub assembly, comprising a glass fiber-polyester laminated bathtub shell having a generally dish-shaped bottom therefor sloped downwardly longitudinally toward a drain end, an attached support device providing beam strength for the bottom constructed of a rigid monolithic layer of hardened binder material having l0 to 75 volume percent porosity and having its top surface contoured to conform to the shell bottom and secured thereto, and elongated longitudinally and laterally eX- tending support beams proteetively surrounding said layer and secured to the shell bottom.

References Cited in the tile of this patent UNITED STATES PATENTS 1,355,122 Bintliff Oct. l2, 1920 2,346,942 Rodman Apr. 18, 1944 2,534,147 Rodman Dec. l2, 1950 2,695,256 De Olloqui et al Nov. 23, 1954 FOREIGN PATENTS 562,587 Great Britain uly 7, 1944 

